A heat exchanger is conventionally developed, which includes flow paths, which a heat-exchange fluid passes through, and which are formed on surfaces of sheet metals, such as stainless steel plates or aluminum plates, by means of etching technique or the like. As such a heat exchanger, a heat exchanger described in Patent Literature 1 is known, for example.
This heat exchanger is constituted by alternately stacking metal sheet-like plates each provided with a plurality of heat transfer fins. A flow path for heat-exchange fluid is formed between each of the two opposed metal sheet-like plates. In the thus-constituted heat exchanger, each of the heat transfer fins is formed such that it has a cross-section that is curved from its front end to its rear end, and the area of a flow path for a fluid, which flows between the heat transfer fins, is substantially constant.
This structure can minimize pressure loss due to contracted flow or expanded flow of the heat-exchange fluid flowing through the flow path. Further, the pressure loss of the heat-exchange fluid can be minimized while reduction in size and cost of the heat exchanger are maintained, and the heat transfer performance of the heat exchanger is not impaired.